Tow-component sealant comprising cross-linked polyalkylene oxide

ABSTRACT

The present invention relates to a two-component sealant comprising a first part and a second part wherein 
     a) the first part (X) comprises:
         (i) a polyalkyleneoxide polymer having one or more unsaturated end groups   (ii) an addition reaction catalyst       

     b) the second part (Y) comprises:
         (i) an organosiloxane comprising one or more Si—H groups.       

     The present invention also relates to medical devices used in connection with the sealant, mixing devices for delivering and mixing the first part and the second part of the sealant, and methods for applying the sealant.

FIELD OF THE INVENTION

The present invention relates to a novel two-component sealant whichcrosslinks in-situ comprising cross-linked polyalkylene oxide.

The present invention also relates to medical devices used in connectionwith the sealant, mixing devices for delivering and mixing the firstpart and the second part of the sealant, and methods for applying thesealant.

BACKGROUND OF THE INVENTION

Surgical procedures, known as ostomies, are some times necessitated dueto inflammatory bowel disease, cancer, or injury. An ostomy creates anartificial opening (stoma) in the abdomen for the elimination of bodilywaste. Since the ostomy patients are unable to control the passage ofbodily waste material, use is made of an appliance attached to the bodyto collect this material. Conventional available ostomy appliancesconsist of a pouch, made up of a barrier plastic material, attached to ahydrocolloid containing synthetic rubber based adhesive gasket capableof adhering to the skin around the stoma. The adhesive gasket is capableof anchoring the appliance to the skin for time periods ranging from afew hours to as long as 10 days. The adhesive gasket does protect theperistomal skin. However, it is very difficult for the ostomate to cut ahole in the wafer to fit perfectly around the stoma to achieve a fluidproof seal between the stomal opening of the gasket and the stoma. Evenfor pre-cut adhesive gaskets it can be difficult to obtain at perfectfit around the stoma, to achieve a fluid proof seal between the stomalopening of the gasket and the stoma. Therefore, some areas of theperistomal skin may remain exposed and become vulnerable to thedeleterious effects of the intestinal effluents, which can cause seriousirritation, excoriation, and eventual breakdown of the skin contiguousto the stoma. In addition, the fluid leakage may also causedisintegration of the gasket, resulting in breach of its barrierproperties and exacerbating the problem of skin protection. Anotherfrequent cause of peristomal skin complications is stomal effluentundermining a skin barrier due to irregularities in stoma placement,stoma shape, retraction or scarring. When peristomal surface unevennessis severe, the appliance gasket may fail to achieve an acceptable sealresulting in undermining of the gasket by the stomal effluent, causingleakage, discomfort and pain. For these reasons, many ostomates use oneof the additional means available in the form of pastes, hydrocolloidpowders, karaya seal rings, skin barrier rings, or adhesive strips toaugment the sealing function of the gasket. One of the disadvantages ofsuch pastes is that some of them contain solvents, which are irritatingto skin. Another disadvantage is that the pastes are easily subject todisintegration by absorption of effluent or moisture. Pastes aregenerally not very cohesive, and therefore often leave residues uponremoval. Body movements could also disrupt the sealing properties.Thorough cleaning is required in order that a new plaster may stick wellto the application area. This procedure may further irritate the skin.

U.S. Pat. No. 4,204,540 describes a composition adapted for use aroundthe stoma and consisting of a homogeneous mixture of apressure-sensitive adhesive component, mineral oil, and hydrocolloidgums or cohesive strengthening agents or a mixture of hydrocolloid gumsand cohesive strengthening agents. A balance of different components inthe mixture provides compositions which can be shaped by hand to sealthe skin surface between the gasket and the stoma.

U.S. Pat. No. 4,231,369 describes a gel-like sealant compositioncomposed of a physical mixture of tackified styrene-olefin-styrene blockcopolymer having at least one hydrocolloid dispersed therein.

U.S. Pat. No. 4,350,785 describes an ostomy paste formulated as mixturesof water absorbing particulate hydrocolloid gums and organic solvent(e.g. alcohol) solutions of adhesive film forming resins, such aspoly(methyl vinyl ether/maleic acid), having increased resistance tourine and intestinal fluids by incorporating a small amount of colloidalsilica, preferably fumed silica.

U.S. Pat. No. 4,578,065 describes protective sealing compositions in theform of molded rings or sheets, which comprise gelled mixtures of waterabsorbing particulate hydrocolloid gum and non-toxic polyhydroxyalcohol,having increased resistance to the drained fluid (e.g. urine orintestinal fluids) by incorporating a small amount of fumed silica orcolloidal silica gel.

U.S. Pat. No. 4,477,325 to Osburn describes sealant or paste compositionof hydrocolloids in a network of an elastomeric copolymer of ethyleneand vinyl acetate, and polyisobutylene; the mechanical strength andfluid endurance of which is enhanced by crosslinking, produced byirrradiating the mixture.

U.S. Pat. No. 4,738,257 to Meyer et al describes a continuouselastomeric phase, formed by cross-linking to form a network, anddistinguishes itself by stating that in Sorensen and Osburn, above, thatafter absorbing enough water, the hydrocolloid loses its wet tack, orability to adhere to the skin to form a sealant or shield.

U.S. Pat. No. 5,496,296 describes an ostomy appliance having an adhesivegasket, which includes a flexible patch which may be formed of non-wovenmaterial and is covered on one side with a first layer of moistureabsorbing pressure-sensitive adhesive material surrounding the stomalopening, and a second layer of a soft, easily deformable, extrudablefluid resistant gasket that prevents stomal fluids form contacting theperistomal skin surfaces and the first layer of the adhesive andpossibly dissolving that layer and/or disrupting its attachment to skin.

WO 2006/075949 describes a pre-formed, very soft sealant ring. It ispre-formed, and so can be limited as to how well it can adapt to avariety of skin sites of different shapes or sizes. The preferredmaterial is described to be silicone rubber, which has adhesion problemsto most materials, including SIS and PIB, the common material used forostomy adhesive plates.

The best fitting sealant achievable would come from a flowable orpliable system which wets out easily into the contours and crevices ofthe skin and adapts to the surface of the skin. There should also be anincrease in cohesion after application for it to function safely and tobe easy removable after use.

U.S. Pat. No. 6,068,852 describes a 2 part, polymerizable, skin sealantor shield which cures in-situ at the skin site. It describes the use ofacrylic copolymers and monomers which are crosslinked by the use of freeradical polymerization initiator.

Acrylic monomers and free radical initiators are known to be toxic toskin. The initiator can also be inhibited by the applicationenvironment, such as oxygen, moisture and pH, so that crosslinking cannot be achieved effectively. Furthermore, the above mentioned systemsuse relatively low to very low moisture permeable polymers which are notinducive to transporting moisture away from the skin, giving potentialmaceration problems.

One solution is to increase the amount of water absorbent material,which has the effect of swelling or weakening the polymer matrix. Thisin turn reduces the sealing or adhesion properties and the erosionresistance of the seal, leading to reduced wear time and leakageproblems.

WO04108175 discloses a 2 component silicone composition for applicationto the skin.

JP2004067720 discloses a crosslinked polyoxyalkylene based polymermatrix which is pre-reacted at 90° C. on a fabric carrier. Both reactioncomponents for the crosslinked polymer are silicone oligomers orcopolymers.

Silicone systems, due to the nature of their surface properties, haveadhesion problems with most commonly used adhesives in the medicalapplications of interest except with silicone based devices. Thisseverely limits the usability of silicone compositions. Furthermore,silicones in general do not have very high water transport properties,thus may lead to maceration problems.

WO 2005/032401 describes a PSA sheet based on PPO polymers having lowirritation to the skin and high moisture permeability. It is apre-formed adhesive crosslinked at over 100° C.

It has now been surprisingly found that liquid PPO polymers can becrosslinked at workable rates at body temperatures on the skin site toprovide a very good fit around the contours of the skin site, therebyproviding very good sealing or barrier properties against leakage aroundthe stoma. It is soft and comfortable to wear, easy to remove in onepiece, skin friendly, and does not cause adhesion problems when laterusing other types of adhesives.

Furthermore, it provides superior moisture permeability, excellenterosion resistance, again improving safety against leakage, fast curingof between 5 to 30 min. under application conditions.

SUMMARY OF THE INVENTION

Accordingly, the present invention relates to a two-component sealantcomprising a first part and a second part wherein

a) the first part (X) comprises:

-   -   (i) a polyalkyleneoxide polymer having one or more unsaturated        end groups    -   (ii) an addition reaction catalyst

b) the second part (Y) comprises:

-   -   (i) an organosiloxane comprising one or more Si—H groups.

The present invention also relates to medical devices used in connectionwith the sealant, mixing devices for delivering and mixing the firstpart and the second part of the sealant, and methods for applying thesealant.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a two-component sealant as describedabove which can be crosslinked at workable rates at body temperatures onthe skin site to provide a very good fit around the contours of the skinsite, thereby providing very good sealing or barrier properties againstleakage around stoma. It is soft and comfortable to wear, but easy toremove in one piece, skin friendly, and does not cause adhesion problemswith replacement adhesives.

According to one embodiment of the invention, the first part (X)comprises:

-   -   (i) a polyalkyleneoxide polymer having one or more unsaturated        end groups, and wherein more than 90% w/w of the polyalkylene        oxide polymer consist of polymerised alkyleneoxide moities        having three or more carbon atoms, and    -   (ii) an addition reaction catalyst

b) the second part (Y) comprises:

-   -   (i) an organosiloxane comprising one or more Si—H groups.

According to another embodiment of the invention, the first part (X)comprises:

-   -   (i) a polyalkyleneoxide polymer having at least two unsaturated        end groups, and wherein more than 90 % w/w of the polyalkylene        oxide polymer consist of polymerised alkyleneoxide moities        having three or more carbon atoms, and    -   (ii) an addition reaction catalyst

b) the second part (Y) comprises:

-   -   (i) a polysiloxane cross-linking agent comprising 3 or more Si—H        groups and optionally    -   (ii) a polysiloxane chain extender comprising up to 2 Si—H        groups.

According to a preferred embodiment of the invention the second partcomprising a polyalkyleneoxide polymer of the type that is defined to beused in the first part.

According to a preferred embodiment of the invention the first partcomprises the polyalkyleneoxide polymer in amounts of 80-98% w/w and theaddition reaction catalyst in amounts of 0.01-1% w/w and the second partcomprises the polyalkyleneoxide polymer in amounts of 0 to 98,preferably 80-98% w/w and the siloxane in amounts of 1-100, preferably1-10% w/w.

The sealant of the invention may comprise the above mentionedingredients, as well as other ingredients, such as other polymers orpolymeric product.

The polyalkylene oxide polymer having one or more unsaturated groups maybe branched or linear.

However, suitably, the polyalkylene oxide polymer is linear and has twounsaturated end groups.

In one particular embodiment of the invention the polyalkylene oxidepolymer is polypropyleneoxide.

The polypropylene oxide having unsaturated end groups may be a compoundof formula

CH₂═C(R¹)-(Z)-O—(X)_(n)—(W)—C(R²)═CH₂   (Ia)

or

CH(R¹)═CH-(Z)-O—(X)_(n)—(W)—CH═CH(R²)   (Ib)

wherein

R¹ and R² are independently selected from hydrogen and C₁₋₆-alkyl;

Z and W is C₁₋₄-alkylene;

X is —(CH₂)₃—O— or —CH₂—CH(CH₃)—O—; and

n is 1-900, more preferred 10-600, or most preferred 20-600.

The number average molecular weight of the polyalkylene oxide havingunsaturated end groups is suitably between 500 and 100000, morepreferred between 500 and 50,000 and most preferred between 1000 and35,000.

Polypropylene oxide having unsaturated end groups may be prepared asdescribed in U.S. Pat. No. 6,248,915 and WO 05/032401 or analogously tothe methods described therein. Other polyalkylene oxide polymers may beprepared analogously.

The polysiloxane cross-linking agent comprising 3 or more Si—H groups issuitable a compound having the formula

R—SiO(R, R)—(SiO(R,R))_(m)—Si—(R,R,R)   (II)

wherein

at least three of the groups R is hydrogen and the rest of the groups Rare each independently selected from C₁₋₁₂-alkyl, C₃₋₈-cycloalkyl,C₆₋₁₄-aryl, and C₇₋₁₂-arylalkyl; and

m is 5-50, or preferably 10-40. The number average molecular weight asdetermined by GPC is suitably 500-3000.

One or more cross-linking agents of formula (II) may be used in thesecond part of the two-component sealant.

In one embodiment of the invention, a mixture of one or morecross-linking agents of formula (II) comprising 3 or more Si—H groupsand a polysiloxane chain extender comprising up to 2 Si—H groups is usedin the cross-linking reaction.

The polysiloxane chain extender is suitably a compound having theformula

R³—SiO(R³, R³)—(SiO(R³,R³))_(m)—Si—(R³,R³,R³)   (III)

wherein

up to 2 of the groups R³ is hydrogen and the rest of the groups R³ areeach independently selected from C₁₋₁₂-alkyl, C₃₋₈-cycloalkyl,C₆₋₁₄-aryl, and C₇₋₁₂-arylalkyl; and

m is 0-50. The number average molecular weight as determined by GPC issuitably between 200 and 65000, most preferably between 200 and 17500.

As used herein C₁₋₁₂-alkyl means a linear or branched alkyl group having1 to 12 carbon atoms, C₁₋₈-alkyl means a linear or branched alkyl grouphaving 1 to 8 carbon atoms, and C₁₋₆-alkyl means a linear or branchedalkyl group having 1 to 6 carbon atoms, such as methyl, ethyl, propyl,isopropyl, butyl, pentyl and hexyl.

As used herein C₁₋₄-alkylene means a linear or branched divalentalkylene group having 1 to 4 carbon atoms, such as methylene, ethylene,propylene, isopropylene, butylenes and isobutylene.

As used herein C₃₋₈-cycloalkyl means a cyclic alkyl group having 3-8carbon atoms, such as cyclopentyl and cyclohexyl.

As used herein C₆₋₁₄-aryl means a phenyl or naphthyl group optionallysubstituted with C₁₋₆-alkyl, such as tolyl and xylyl.

As used herein C₇₋₁₂-arylalkyl means aryl attached to a C₁₋₆-alkylgroup, where C₁₋₆-alkyl and aryl is as defined above, such as benzyl,phenethyl and o-methylphenethyl.

In the compound of formula (II) and in the compound of formula (III),the groups R and R³, which are not hydrogen, are suitably eachindependently selected from a member of the group C₁₋₆-alkyl, C₆₋₁₄-arylor C₇₋₁₂-arylalkyl.

The Si—H groups may be situated at either end of the compound of formula(II). However, at least one Si—H group is preferably positioned withinthe —(SiO(R³,R³))_(m)— chain of the compound of formula (II).

The polysiloxane cross-linking agent and the chain extender may beprepared as described in Japanese Patent Application 2002-224706 and WO05/032401 or analogously to the methods described therein.

An addition reaction is, in its simplest terms, a chemical reaction inwhich the atoms of an element or compound react with a double bond ortriple bond in an organic compound by opening up one of the bonds andbecoming attached to it, forming one larger compound.

Addition reactions are limited to chemical compounds that havemultiple-bonded atoms.

Hydrosilylation is an addition reaction between, for example, acarbon-carbon double bond in a compound and a reactive hydrogen from ahydrogen siloxane.

Suitable addition reaction catalysts are any hydrosilylation catalysts,preferably platinum (Pt) catalysts. Pt-catalysts for the first part ofthe two-component sealant are described in U.S. Pat. No. 6,248,915. Inconsideration of toxicity potential, Pt complex catalyst where Pt is ata valency state of zero is preferred. Preferred catalysts areplatinum-vinylsiloxan and platinum-olefin complexes, such as Pt-divinyltetramethyl disiloxane.

The two components are mixed immediately before delivery. A wide rangeof devices for delivering and mixing the two components can be used.

The mixing and reaction is suitably carried out at room to bodytemperature between 25° C. and 40° C. It is not necessary to use asolvent for the reaction, which is an advantage, but especially in thepreparation of sealants for skin applications.

Suitably, the ratio of the number of reactive Si—H groups in thepolysiloxane cross-linking agent to the number of unsaturated groups inthe polypropylene oxide, which are reactive with Si—H groups under thereaction conditions, is between 0.2 and 1.0.

The amount of polysiloxane used for the cross-linking is suitably lessthan 15% w/w, and more preferred below 10% w/w of the amount ofpolyalkylene oxide polymer having unsaturated end groups.

The cross-linking reaction does not lead to complete cross-linking ofall the polyalkylene oxide polymers. The sealant comprises a mixture ofcross-linked and non cross-linked polyalkylene oxide polymer.

Good moisture handling is important for skin applications. Management ofmoisture from skin can be by permeation or absorption or both methodsthrough the sealant.

In some applications high permeability without water absorption ispreferred as this transports the moisture away from the skin surface,without sacrificing other properties such as erosion resistance andswelling resistance.

The addition of hydrocolloid or other organic or inorganic moistureabsorbing particles or polymers is also feasible to improve the moisturehandling properties. The type and amount added will influence otherparameters such as mechanical and erosion properties and water vaportransmission.

According to a preferred embodiment of the invention one or both of thefirst part and the second part comprising one or more hydrocolloids inamounts of 5-35% w/w.

According to another preferred embodiment of the invention one or bothof the first part and the second part do not comprise hydrocolloids.

Optionally, non absorbent particles or polymers, such as potatoe starch,may be added to the composition. These fillers do not affect themoisture absorption characteristics significantly. They are especiallyuseful in reducing the concentrations of active ingredients, loweringtoxicity potential and costs. Further these fillers may also effect themechanical properties of the final system in regards to hardness andadhesion.

According to a preferred embodiment of the invention one or both of thefirst part and the second part comprising a filler and/or a stabilizerin the amounts of 0.5-65% w/w with the polymer in the amounts from35-98% w/w.

Another optional ingredient is a rheological modifier, such asthixotropic or anti-settling agents. These help to control and modifythe viscosity to suit the application method, and prevent thesedimentation of other particulate ingredients. Examples include fumedor colloidal silica, e.g. Aerosil 202 from Degussa.

According to a preferred embodiment of the invention one or both of thefirst part and the second part comprising a rheological modifier inamounts of 0.1-10% w/w.

Oils, tackifiers, plasticisers may be also added to modify properties.

Other optional functional ingredients include colouring agents, organicor inorganic pigments, such as iron oxide, to give a distinctive colourto one or both components for easy identification and help withfollowing the mixing. Other ingredients may include antioxidants, pHbuffers. Furthermore ingredients such as aloe vera or other functionalingredients eg. skinfriendliness can be added to one or both componentsof the composition.

According to a preferred embodiment of the invention one or both of thefirst part and the second part comprise one or more functionaladditives.

The composition of the invention is compatible with and can adhere to awide variety of adhesives with which it is intended to cooperate, andcan therefore be removed with a typical adhesive used with a standardmedical device in one piece without leaving residue, or oil, which makereplacement adhesives difficult to stick. Examples of such adhesivesinclude PPO adhesives described in WO 2005/032401, and hot-meltadhesives as described in U.S. Pat. No. 5,559,165.

Another embodiment of the invention is that the invention compositioncan be easily separated from the adhesive plate of the medical device,while still attached to the skin, when the device is removed, so that itcan be removed in one piece separately.

The invention also relates to medical devices comprising a sealant asdescribed above. The invention is especially suitable to be used inconjunction with medical devices for ostomy applications.

The present invention can be mixed by a number of well known methodstypical for mixing 2 component systems and applied directly onto theskin area, followed by the application of the ostomy device with anadhesive plate for attachment to the skin.

Alternatively, the mixed sealant can be applied around the centralopening of the adhesive plate of the ostomy device, and the device isplaced at the stoma as normal.

According to a preferred embodiment of the invention a method for makinga custom made, skin friendly, protective, aqueous fluid managing skinseal or shield using a two-component sealant according to the invention,comprises the steps,

(i) mixing parts one and two to form a paste,

(ii) applying the paste to the area of the skin where a seal or shieldis desired,

in sufficient quantity to allow the paste to flow into the contours,folds, and crevices of the skin, and therein undergo self curing to forma soft, flexible and coherent rubbery mass, tightly adhering to theskin.

According to another preferred embodiment of the invention a method formaking a custom made, skin friendly, protective, aqueous fluid managingskin seal or shield using a two-component sealant according to theinvention, comprises the steps,

(i) mixing parts one and two to form a paste,

(ii) applying the appliance or device to the skin site,

(iii) then applying the paste into or onto the visible crevice or skinsite, where after the paste undergoes self curing to form a soft,flexible and coherent rubbery mass, tightly adhering to the skin.

According to yet another preferred embodiment of the invention a methodfor making a custom made, skin friendly, protective, aqueous fluidmanaging skin seal or shield using a two-component sealant according tothe invention, comprises the steps,

(i) mixing parts one and two to form a paste,

(ii) applying to an appliance or device to be attached to the skin, asufficient quantity of the paste to allow the paste to flow into thecontours, folds, and crevices of the skin when applied, and,

(iii) applying the apparatus or device to the skin within a short periodof time, 1-30 minutes preferably 5-15 minutes, of mixing parts one andtwo, whereafter the paste undergoes self curing to form a soft, flexibleand coherent rubbery mass, tightly adhering to the skin.

The invention may also have other skin protecting applications, such asuse with devices for the management of fecal incontinence and for usearound fluid drainage openings like wound or surgical incision sites.

The sealant according to the invention may also be used to create aprotective barrier to prevent skin damage.

The present invention could also be used for any applications where theskin will benefit from a soft, comfortable, moisture handling protectivelayer, e.g. masks.

One embodiment of the invention relates to a delivery device for thetwo-component sealant according to the invention wherein said deliverydevice dispensing said sealant in the necessary ratios of the first partto the second part to form the desired sealant.

A wide range of devices for delivering and mixing the first part and thesecond part are known. The choice of device for delivering the firstpart and the second part of the sealant can influence ease of use,handling, viscosity, mixing, curing, and cost. An example of a mixingand delivery device can be a 2-chamber syringe fitted with a staticmixer. Other devices could be a 2 chamber bag for 1 or more times use.The device could also be as simple as 2 vials or more containing thefirst part and the second part, from were the two parts are poured andmixed by hand. The device could be powered by hand or e.g. by air/gaspressure. The sealant could be applied as a foam or a thin film by meansof aerosol.

Experimental

The following materials were used in the experimental part:

HPM-502=methyl hydrosiloxane—phenyl methyl siloxane copolymer, hydrideterminated, 75-110 cs, from ABCR

AA2000=Polypropylenglykol 2000, allyl-terminated polyether (polypropylene oxide), from Clariant

Catalyst Pt-VTS. Pt-VTS is Pt-divinyl tetramethyl disiloxane in IPA (Pt3.0 wt %).

Aerosil® R202, fumed silica anti-settling agent from Degussa

ACX003, allyl-terminated polyether (poly propylene oxide) viscosity 16Pa·s from Kaneka.

CR500, poly-alkyl hydrogen siloxane curing agent available from Kaneka.

Silicone A: Dow Corning 9800 Part A

Silicone B: Dow Corning 9800 Part B

PU film: BL9601, Intellicoat. MVTR=10000 g/m²/24 h

Bayferrox 960, iron oxide powder from Lanxess

Aquasorb A500, sodium carboxymethyl cellulose, Aqualon

Examples for Component A

Put the ingredients, PPG AA2000, Pt-VTS at the correct weights in acontainer. Stir to mix using a wooden spatula. If fillers are added,then add filler in small increments and mix. Finally adjust viscositywith Aerosil® R202 by adding in small increments and mixing until asmooth mixture is obtained without any grittiness or lumps.

Examples for Component B

Put the ingredients, PPG AA2000, HPM-502 at the correct weights in acontainer. Stir to mix using a wooden spatula. If fillers are added,then add filler in small increments and mix. Finally adjust viscositywith Aerosil® R202 by adding in small increments and mixing until asmooth mixture is obtained without any grittiness or lumps.

Examples of Mixing Sealants

Add 1 part component A (containing catalyst) to 1 part component B(containing Silicone crosslinker). Mix thoroughly using a wooden spatulafor 2-5 min.

Gelation is visually determined when the mixture is no longer fluid orpaste-like.

Compositions

Component A1 B1 B2 A2 B3 A3 B4 B5 A4 B6 PPG AA2000 48.55 44.64 44.2648.44 91.77 99.60 80.12 93.68 HPM-502 4.00 4.38 8.23 19.88 6.32 ACX00349.16 45.72 CR500 3.67 Pt-VTS 0.09 0.19 0.40 0.24 Aquasorb A500 20.0020.00 Potatoe starch 48.64 48.64 48.64 48.64 29.40 29.40 Aerosil ® R2022.72 2.72 2.72 2.72 1.20 1.20 Bayferrox 960 0.01 Ingredients in w/w %

Sealant Compositions and Results

A1 + B1 not gelled A2 + B1 gelled within 20 min RT A2 + B2 gelled within20 min RT

The above results show examples where fillers and additives are used.The catalyst must be above a certain level to achieve good reaction atroom temperature. But catalyst is also very expensive, and so it is keptat the lowest level to achieve good reaction at room temperature (RT)for it to be useful commercially.

A3 + B3 gelled within 20 min RT A3 + B4 gelled within 5 min RT A3 + B5not gelled

The above results show sealant compositions without fillers. Thecrosslinker level must be sufficiently high in order to achieve a gel ofthe required cohesion for good sealant properties, and to achievegelation in practical times, typical 5-30 min.

Methods

Determination of moisture vapour transmission rate (MVTR) MVTR ismeasured in grams per square meter (g/m²) over a 24 hours period usingan inverted cup method.

A container or cup that is water and water vapour impermeable having anopening is used. 20 ml saline water (0.9% NaCl in demineralised water)is placed in the container and the opening is sealed with the test film.The container, with a duplicate, is placed into an electrically heatedhumidity cabinet and the container or cup is placed up side down suchthat the water is in contact with the adhesive. The cabinet ismaintained at 37° C. and 15% relative humidity (RH). After about anhour, the containers are considered to be in equilibrium with thesurroundings and it is weighed. 24 h after the first weighing, thecontainers are weighed again. The difference in weight is due toevaporation of vapour transmitted through the test film. This differenceis used to calculate Moisture vapour transmission rate or MVTR. MVTR iscalculated as the weight loss after 24 h divided by the area of theopening in the cup (g/m²/24 h). An error is introduced by using asupporting PU film. However, the water permeability of the used film isvery high (10000 g/m²/24 h) and the error that is introduced istherefore very small.

Example of Sealant Prepared by A4 and B6

A sealant of the invention was prepared by mixing 1 part of A4 and 1part of B6. The components were mixed thoroughly using a wooden spatulafor 2-5 min. To produce the sheet stock, the mixture was coated on asilicone coated release liner. Coating thickness was 1000 μm. Thesamples are cured at room temperature for 20 min.

Comparative Example C1

First, 4 parts of Silicone A and 4 parts of Silicone B were weighed andmixed thoroughly with a spetula and after that, 2 parts Aquasorb wasadded.

After mixing for approx. 5 min., the mixture was formed into a sheetstock material having a thickness of approximately 0.3 mm by coating alayer onto a 30 μm PU film (Inspire 2301 from Intelicoat). The sampleswere cured at 100° C. for 1 hr in order to ensure complete reaction.Then it was cooled to ambient temperature ready for use. The resultantflat plate was cut into the desired shapes.

MVTR Results

Composition Thickness/mm MVTR/g/m²/24 hr A4 + B6 1.00 600 C1 0.30 378

As can be seen, the invention at higher thickness than a comparisonexample of silicone gel still gives significantly higher permeability.Hence the invention sealant is desirably more permeable than, forexample, a similar system based on silicone, making the currentinvention highly preferable for the intended applications.

1. A two-component sealant comprising a first part and a second partcharacterised in that a) the first part (X) comprises: (i) apolyalkyleneoxide polymer having one or more unsaturated end groups (ii)an addition reaction catalyst b) the second part (Y) comprises: (i) anorganosiloxane comprising one or more Si—H groups.
 2. The two-componentsealant according to claim 1 wherein a) the first part (X) comprises:(i) a polyalkyleneoxide polymer having one or more unsaturated endgroups, and wherein more than 90% w/w of the polyalkylene oxide polymerconsist of polymerised alkyleneoxide moities having three or more carbonatoms, and (ii) an addition reaction catalyst b) the second part (Y)comprises: (i) an organosiloxane comprising one or more Si—H groups. 3.The two-component sealant according to claim 1 wherein a) the first part(X) comprises: (i) a polyalkyleneoxide polymer having at least twounsaturated end groups, and wherein more than 90% w/w of thepolyalkylene oxide polymer consist of polymerised alkyleneoxide moitieshaving three or more carbon atoms, and (ii) an addition reactioncatalyst b) the second part (Y) comprises: (i) a polysiloxanecross-linking agent comprising 3 or more Si—H groups and optionally (ii)a polysiloxane chain extender comprising up to 2 Si—H groups.
 4. Thetwo-component sealant according to claim 1 wherein the second partcomprising a polyalkyleneoxide polymer of the type that is defined to beused in the first part.
 5. The two-component sealant according to claim1 wherein the addition reaction catalyst is a Pt vinyl siloxane complex.6. The two-component sealant according to claim 1 wherein the first partcomprises the polyalkyleneoxide polymer in amounts of 80-98% w/w and theaddition reaction catalyst in amounts of 0.01-1% w/w and the second partcomprises the polyalkyleneoxide polymer in amounts of 0 to 98,preferably 80-98% w/w and the siloxane in amounts of 1-100, preferably1-10% w/w.
 7. The two-component sealant according to claim 1 wherein oneor both of the first part and the second part comprising a filler and/ora stabilizer in the amounts of 0.5-65% w/w with the polymer in theamounts from 35-98% w/w.
 8. The two-component sealant according to claim1 wherein one or both of the first part and the second part comprising aTheological modifier in amounts of 0.1-10% w/w.
 9. The two-componentsealant according to claim 1 wherein one or both of the first part andthe second part comprising one or more hydrocolloids in amounts of 5-35%w/w.
 10. The two-component sealant according to claim 1 wherein one orboth of the first part and the second part do not comprisehydrocolloids.
 11. The two-component sealant according to claim 1wherein one or both of the first part and the second part comprising oneor more functional additives.
 12. The two-component sealant according toclaim 1 wherein the polyalkylene oxide polymer is polypropyleneoxide.13. A medical device comprising a two-component sealant according toclaim
 1. 14. A medical device according to claim 13 wherein the medicaldevice is an ostomy appliance.
 15. A delivery device for thetwo-component sealant according to claim 1 wherein said delivery devicedispensing said sealant in the necessary ratios of the first part to thesecond part to form the desired sealant.
 16. A delivery device accordingto claims 15 wherein said delivery device comprises a two-chambersyringe fitted with a static mixer.
 17. A method for making a custommade, skin friendly, protective, aqueous fluid managing skin seal orshield using a two-component sealant according to claim 1, comprisingthe steps, (i) mixing parts one and two to form a paste, (ii) applyingthe paste to the area of the skin where a seal or shield is desired, insufficient quantity to allow the paste to flow into the contours, folds,and crevices of the skin, and therein undergo self curing to form asoft, flexible and coherent rubbery mass, tightly adhering to the skin.18. A method for making a custom made, skin friendly, protective,aqueous fluid managing skin seal or shield using a two-component sealantaccording to claim 1, comprising the steps, (i) mixing parts one and twoto form a paste, (ii) applying to an appliance or device to be attachedto the skin, a sufficient quantity of the paste to allow the paste toflow into the contours, folds, and crevices of the skin when applied,and, (iii) applying the apparatus or device to the skin within a shortperiod of time, 1-30 minutes preferably 5-15 minutes, of mixing partsone and two, whereafter the paste undergoes self curing to form a soft,flexible and coherent rubbery mass, tightly adhering to the skin.
 19. Amethod for making a custom made, skin friendly, protective, aqueousfluid managing skin seal or shield using a two-component sealantaccording to claim 1, comprising the steps, (i) mixing parts one and twoto form a paste, (ii) applying the appliance or device to the skin site,(iii) then applying the paste into or onto the visible crevice or skinsite, where after the paste undergoes self curing to form a soft,flexible and coherent rubbery mass, tightly adhering to the skin.